Generally, heart failure is defined as a pathological condition in which heart function is deteriorated by various conditions such as an ischemic heart disease (e.g., myocardial infarction or angina pectoris), cardiomyopathy, or hypertension. Currently available biomarkers for diagnosing such a heart failure include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and N-terminal proBNP (NT-proBNP). Assaying such a marker can determine whether or not a patient suffers from heart failure, and how severe the heart failure is.
However, since the cause of many diseases including heart failure cannot be determined as a single factor, in actual clinical settings a specific disease cannot be definitely diagnosed through assaying only one type of biomarker. In addition, since they are found in blood, urine, etc. in response to progress of pathological conditions, biomarkers may fail to specifically diagnose the target pathological conditions when the progress of the conditions varies among individual patients. Therefore, currently, many diseases are generally diagnosed by use of a variety of markers in combination.